Mattress

ABSTRACT

A mattress comprising a spring assembly consisting of numerous coil springs so arranged as to form a flat plane and frame wires fixed to the springs disposed on the periphery of said arrangement; a sheet of elastic material covering at least the top plane of the spring assembly and those portions of all the four sides of said assembly which are disposed near the corresponding upper edges; a frame-shaped elastic foamed block inserted in a compressed state into the void spaces left in the sides of the spring assembly; and outermost covering enveloping the whole outside of a mattress body.

United States Patent 91 [111 3,848,283

Ikeda Nov. 19, 1974 1 MATTRESS 2,940,089 6/1960 Koenigsberg 5/360 3,089,154 5/1963 Boyles 5/351 [75] Invent JaPa" 3,178,735 4/1965 Thompson a a1. 5/353 [73] Assignee: France Bed Co., Ltd., Tokyo, Japan Primary Examiner-Paul H. Gilliam [22] Flled' 7 Assistant Examinerl(enneth J. Dorner Appl. N0.: 321,078 Attorney, Agent, or Firm--Nolte and Nolte [30] I Foreign Application Priority Data 57 STRA T g j A mattress comprising a spring assembly consisting of f apa 'f numerous coil springs'so arranged as to form a flat V plane and frame wires fixed to the springs disposed on CCll. the periphery of Said arrangement; a sheet of elastic [58] Fie'ld 53 1 353 2 material covering at least the top plane of the spring 5/347 assembly and those portions of all the four sides of said assembly which are disposed near the corresponding upper edges; a frame-shaped elastic foamed block [56] References Cited inserted in a compressed state into the void spaces left UNITED STATES PATENTS in the sides of the spring assembly; and outermost cov- 1,238,302 8/1917 Kronluno 5/351 gring enveloping the whole outside of a mattress body. 1,865,043 6/1932 Pittoni 2,826,769 7 3/1958 Drews 5/351 3 Claims, 8 Drawing Figures 'PATENIU, m 1 9 I974 SHEET 2 OF 3 FIG. 3

FIG. 4

PATENTELNUVISIQI I SHEET 30F 3 MATTRESS This invention relates to a mattress improved in cushioning property.

A mattress in common use includes a rectangular spring assembly which is constructed by arranging numerous coil springs so as to form a fiat plane, joining the coil springs by helical wires, fitting hard steel frame wires along the periphery of both top and bottom planes of a body of coil springs thus joined and connecting said frame wires, for example, through the helical wires, to the coil springs which are disposed on the periphery of the coil spring assembly. The cushioning body of the conventional mattress is formed by mounting an elastic member consisting of, for example, cotton on the aforesaid coil spring assembly with the hard steel frame wires surrounded by the peripheral edge portion of said elastic member. The cushioning body is all enveloped with a covering to finish a mattress.

However, the prior art mattress of the abovementioned construction has its periphery only sup ported by upper and lower frame wires engaging the coil springs disposed on the periphery. Between said frame wires is left a large void space. Where, therefore, the periphery of the mattress is subjected to a load, it is easily distorted due to said void space being contracted, making the user feel instability.

Further with the mattress in common use, the coil springs, helical wires, frame wires, protective covering, elastic member and envelope are all set in place to form an integral body. Accordingly even when there is not applied any direct load on the center of the mattress, a load applied on the periphery of the mattress will pull the mattress as a whole in the direction of the periphery subjected to load and distorted. As the result, the mattress has the drawback that it considerably rocks as a whole. To avoid these shortcomings, it has heretofore been proposed to provide tough edge springs between the upper and lower frame wires. However, even such means failed to attain full improvement in the cushioning property of a mattress.

This invention has been accomplished in view of the above-mentioned circumstances and is intended to provide a mattress which prevents the noticeable distortiori of its periphery under load as is the case with the prior art type and saves the whole mattress from any prominent rocking when it is used.

This invention is characterized in that numerous coil springs are so arranged as to form a flat plane and covered on the plane surface with an elastic member leaving a void around the plane sides and that a frameshaped elastic foamed block having a thickness larger than that of the void spaces left in the sides of the cushioning body is fitted into said void spaces in a compressed state, thereby preventing not only the distortion of the periphery of the mattress but also the rocking of its whole.

Other characteristics of the invention are that the cross section of the frame-shaped foamed block has an outline similar to that of the void spaces left in the sides of the cushioning body, that the inner dimension or diameter of the foamed block is smaller than that of the circular void, and that the insertion of the frameshaped foamed block into the void spaces is effected first by stretching said foamed block around the mattress body utilizing its elasticity and, when released from a stretching force, causing said block to be elastically contracted into the void spaces with close fit, thereby facilitating the assemblyof a mattress.

The present invention can be more fully understood from the following detailed description when taken in connection with reference to the accompanying drawings, in which:

FIG. 1 is a schematic illustration, partly in section, of a mattress body according to an embodiment of this invention;

FIG. 2 is a side view, partly in section, of a mattress body, showing the condition in which a foamed block is fitted into the void spaces left in the sides of a cushioning body shown in FIG. 1;

FIG. 3 is a perspective view of a frame-shaped foamed block used in the invention;

FIG. 4 presents the manner in which the frameshaped foamed block of FIG. 3 is inserted into the void spaces left in the sides of the cushioning body;

8 FIG. 5 is a longitudinal sectional view on line VV of FIG. 3;

FIG. 6 is a longitudinal sectional view of a foamed block modified from that of FIG. 5;

FIG. 7 is a longitudinal sectional view of another modification of FIG. 5; and

FIG. 8 is a side view, partly in section, of a mattress body according to another embodiment of the invention.

There will now be described this invention by reference to the appended drawings.

As seen from FIGS. 1 and 2, the spring assembly of a mattress of this invention consists of numerous coil spring 1 so arranged as to form a flat plane. The adjacent coil springs I are joined by helical wires 2a. Hard steel frame wires 3 are fitted along the periphery of the top and bottom planes of a body of numerous coil springs I joined by said helical wires 2a. The frame wires 3 are fixed to the upper and lower annular ends of the coil springs la disposed on the periphery of the mattress body by means of, for example, helical wires 2b. The top and bottom sides of the coil spring assembly are covered with a protective cloth 4 such as a hessian cloth. Said protective cloth is further covered with an elastic member 5 made of, for example, cotton, thereby forming a cushioning body.

. In this case, the protective cloth 4 and elastic member 5 are made slightly larger than a horizontal plane defined by the spring assembly. Accordingly, the peripheral portions of these coverings 4 and 5 protrude from the edges of the top and bottom sides of the coil spring assembly. Said protruding edge portions 6 are folded about the frame wires 3, with the tips of said protruding edge portions 6 engaged with the peripheral coil springs la by means of a ring 7. In the cushioning body thus constructed, those edge portions 6 of the upper and lower elastic members 5 which are folded along the periphery of the cushioning body define a void space 8 therebetween. The surface of the cushioning body is covered with an enveloping material 10 and a flange ll fitted to the backside of the periphery of said enveloping material 10. Thereafter, the elastic foamed block 9 is forcefully inserted into the void spaces 8 due to its elastic contraction. The foamed block 9 has a thickness larger than that defined by the void spaces 8 left in the sides of the cushioning body. If said thickness defined by the void spaces is indicated,

' for example, by 80, the elastic foamed block 9 is made to have a thickness as large as I00. Therefore, said foamed block 9 is inserted in a fully compressed state into the void spaces 8 so as to attain a cloth fit therewith. The dimensions of the elastic foamed block 9 actually vary with the condition of cells formed by the foaming material used as well as by the elasticity and other physical properties of said foamed block 9. Therefore, it is advised experimentally to determine the dimensions of said foamed block 9. It is further preferred that the foamed block 9 inserted into the void spaces 8 have the outer walls made flush with those of the cushioning body. Thereafter, the sides of the cushioning body are covered with gusset 12 to finish a mattress. The aforesaid flange 11 may be omitted. In this case, it is possible to insert the foamed block 9 into a cushioning body constructed in advance and later cover the cushioning body containing said foamed block 9 with the enveloping material and gusset 12.

The mattress of this invention wherein the foamed block 9 is fitted, as described above, in a compressed state into the void spaces 8 left in the sides of the cushioning body, has larger elastic compressibility than a mattress wherein the void spaces 8 are filled with a foamed block having the same size as the horizontal rectangular plane defined by said void spaces 8, thus attaining an improved cushioning property due to, for example, the prominently increased elastic power of the periphery of the cushioning body. As the result, the periphery of the mattress has substantially as great elasticity as the central part thereof, reducing the instability of said periphery and making the mattress as a whole more comfortable for a user to lie in.

.Though the foamed block 9 used in the mattress of this invention may simply have a block space, yet it is desired that said block 9 be formed into a frame shape as shown in FIGS. 3 and 4 which is similar to the outline jointly defined by the void spaces 8 left in the sides of the cushioning body and that the inner measurements of said block 9 be made equal to, or preferably a little smaller than, the horizontal rectangular plane defined by said void spaces 8. Such a frame-shaped foamed block 9has the advantage that a single operator can easily carry out its insertion by first inserting one side of said block into one of the void spaces 8 and under this condition fitting the remaining three sides thereinto in succession while stretching them, and that, said block can also be mechanically-inserted into the void spaces 8. FIG. 4 shows the manner in which the elastic foamed block 9 is inserted into the void spaces 8 left in the sides of the cushioning body. In this case, the foamed block 9 is stretched at both ends to the phantom position. When the foamed block 9 is released from a stretching force at the desired points on the sides of the cushioning body, then said block elastically contracts itself to be firmly fixed in the prescribed positions on the sides of the cushioning body. It is also possible to bore the sides of the frame-shaped foamed block 9, as shown in FIG. 3, with a plurality of ventilation holes 9a so as to make air more freely pass through the interior of the mattress.

The foamed block 9 used in this invention should preferably consist of an elastic foamed body of plastics material having independent or continuous cells, for example, a foamed body of polyolefin resins or polyurethan. According to this invention, the frameshaped elasticfoamed body 9 has its inner measurements made equal to, or a little smaller than, the horizontal rectangular plane defined by the void spaces 8 left in the sides of the cushioning body. The foamed block 9 is stretched before it is inserted into the void spaces 8. When released from a stretching force, the foamed block 9 elastically contracts itself to be tightly inserted into said void spaces 8. Once fitted, the foamed block 9 need not be additionally fixed to the spring assembly by mechanical or other means so as to prevent its displacement or loosening, thus facilitating the operation of attaching said block to the spring assembly.

The mattress of this invention has further characteristics that the elastic foamed block 9 surrounds the sides of the spring assembly in a compressed state with the cells of said block 9 arranged more compact so as to act as a sort of elastic wall, thereby fully preventing the crosswise rocking of the coil springs l disposed near said block 9; and that said foamed block 9 enables the spring assembly to be rendered more rigid, and consequently even'when the central part of the mattress receives a heavy load, the components constituting the other sections of the mattress are prevented from being unnecessarily stretched or compressed or otherwise affected by said load, thereby making the mattress as a whole prominently comfortable for a user to lie in. Referring to the embodiment of FIG. 3, the frameshaped foamed block 9 has a substantially rectangular longitudinal section as shown in FIGS. 4 and 5. However, the block 9 may have such a shape as is formed by cutting away, as shown in FIG. 6, its inner edges or angular portions. The void spaces 8 into which the foamed block 9 is to be inserted have a cross section whose upper and lower planes are progressively drawn nearer to each other toward the center of the mattress, namely, take a downthrown V-shape. If, therefore, the upper and lower inner angular portions of the foamed block 9 are cut away into a taper form 13, as shown in FIG. 6, so as to substantially match the cross section of the void spaces 8, then said foamed block 9 can be easily inserted into the void spaces 8. Moreover, the whole foamed block 9 is uniformly compressed, preventing its inside from being excessively compressed. Accordingly, there is no possibility of the foamed block 9 swelling outward to deform the sides of the mattress.

The foregoing embodiment refers to the so-called two-face mattress whose upper and lower planes can be used. However, the invention is also applicable to the so-called bottomless mattress having, as shown in FIG. 8, one side alone formed of an elastic material and the other side made of a wooden frame 14. In this case, it is advised to use a foamed block 15 having such a cross section as shown in FIG. 7. The other components of FIG. 8 are the same as those of the preceding embodiment, description thereof being omitted.

What is claimed is:

l. A mattress comprising a plurality of coil springs juxtaposed side-by-side one another so as to form a flat plane, at least one frame wire fixed to said springs and running about the periphery of said flat plane to define a top plane and to form said coil springs into a unitary spring assembly, a sheet of an elastic material covering at least said top plane and having and edge portion covering only a portion of the side of said spring assembly and being formed with first surface means, second surface means opposing said first surface means in spaced relationjthereto, said first surface means diverging out- I wardly with respect to the plane of said second surface means, said first and second surface means defining a means for exerting a vertical compression against said block and for retaining said block in said void.

' 2. A mattress according to claim 1 wherein the void space left in the sides of the spring assembly has a cross section whose upper and lower planes defined by said first and second surface means are progressively drawn nearer to each other toward the center of the mattress, and the foamed block has its inner angular portions cut away into a taper form so as to match the cross section of the void space.

3. A mattress according to claim 1 wherein the foamed block has its sides bored with a plurality of ventilation holes. 

1. A mattress comprising a plurality of coil springs juxtaposed side-by-side one another so as to form a flat plane, at least one frame wire fixed to said springs and running about the periphery of said flat plane to define a top plane and to form said coil springs into a unitary spring assembly, a sheet of an elastic material covering at least said top plane and having and edge portion covering only a portion of the side of said spring assembly and being formed with first surface means, second surface means opposing said first surface means in spaced relation thereto, said first surface means diverging outwardly with respect to the plane of said second surface means, said first and second surface means defining a void space around the side periphery of said spring assembly, an endless elastic stretchable foam block filling said void, said elastic foamed block being in its vertical plane in a state of compression, said elastic foamed block having a normal inner width or length, when at no degree of stretch, less than the length or width of said block in said void, whereby said endless block in said void is under forces which tend to draw said block inward said first and second surface means constituting means for exerting a vertical compression against said block and for retaining said block in said void.
 2. A mattress according to claim 1 wherein the void space left in the sides of the spring assembly has a cross section whose upper and lower planes defined by said first and second surface means are progressively drawn nearer to each other toward the center of the mattress, and The foamed block has its inner angular portions cut away into a taper form so as to match the cross section of the void space.
 3. A mattress according to claim 1 wherein the foamed block has its sides bored with a plurality of ventilation holes. 